控蘖剂对超级杂交早稻金优458生长发育及产量形成的影响

Effects of Tiller-inhibitor on Growth and Yield Formation of Early Sup er Hybrid Rice Jinyou 458

研究了控蘖剂对超级杂交早稻金优458生长发育及产量形成的影响。结果表明:喷施控蘖剂能减少无效和低效分蘖的发生,增加高峰苗期分蘖构成中高效分蘖(4叶及以上分蘖)所占比重;喷施控蘖剂处理的穗长、穗粒数、穗着粒密度、二次枝粳数及着生其上的二次颖花数和结实率均显著高于未喷施控蘖剂的对照;同时喷施控蘖剂能增加株高、中后期群体生物量和叶面积指数,提高孕穗期上3叶叶温和群体透光性,增加叶片SPAD值,从而增强光合作用能力,但也表现出稻株节间长度增加,茎秆粗度减小等特点。喷施控蘖剂处理最终表现为茎蘖成穗率、有效穗数、穗粒数、结实率和千粒重协调提高而增加产量。

The effects of the tiller-inhibitor（TI） on th e growth and yield formation of the early super hybrid rice Jinyou 458 were stud ied.Compared with the check（no TI sprayed）,the TI treatment（1.5 kg/hm2 of TI sprayed at the SN-n stage or critical leaf stage of effective tillers; N=No.of leaves on main culm,n=No.of elongated internodes） reduced invalid an d smaller tillers resulting in a marked increase of the proportion of the big ef fective tillers with 4 or more leaves at the maximal tiller stage,increased the panicle length,spikelets per panicle,spikelet density,secondary branches and the spikelets and seed setting rate on them,plant height and LAI and biomass i n the middle and late growing stages,strengthened the photosynthetic capacity b y increasing leaf temperature of the top three leaves and improving the populati on light transmission at the booting stage and raising the leaf SPAD values,but it elongated the internodes of plants and decreased the stem thickness.Therefo re,the TI treatment finally increased the grain yield for a coordinative improv ement in such characteristics as the panicle-bearing tiller rate,productive pa nicles,spikelets per panicle,seed setting rate and grain weight.